Mobile communications devices are becoming more compact while their functions and features are ever expanding. As a next step in this process of expanding applications, a digital camera may be installed. This requires a new cycle of development with respect to the digital camera in order to package the necessary functions within the compact profile of the mobile communications device. In order to miniaturize the camera for such use, the zoom feature is often eliminated or substantially reduced in functionality. This is because the apparatus needed to move the lens in a traditional zoom mechanism is cumbersome. The development is facilitated by the introduction of digital, semi-conductor, imaging sensors, such as CCD and C-MOS sensor arrays.
In addition a new class of micro-miniature components have become available that provide the functionality of both electrical and mechanical components. These components are fabricated in a process similar to the manufacture of integrated circuit chips, namely the surface treatment of silicon wafers. These mechanisms can provide the function of sensors (resonators), actuators, transducers, motors, and gears to high tolerances. By micro-machining silicon wafers layered on a substrate, the components, of the so called micro-electromechanical system (MEMS), are constructed on a thin substrate. A description of MEMS components is contained in Philosophical Transactions of the Royal Society: Physical Sciences and Engineering, Series A, Issue No. 1703, Dec. 15, 1995, pp. 355-366, which is incorporated herein by reference.
It is a purpose of this invention to provide an autofocus and zoom system for a compact electronic device. A further purpose of this invention is to provide these functions by using a sensor array, such as a C-MOS sensor array, and a lens actuation mechanism suitable for fabrication on a silicon wafer. It is a further purpose of this invention to utilize the advantages of micro-electromechanical system (MEMS) manufacturing techniques to obtain these goals.